Concrete floors in multistory buildings are poured onto flat plywood decks that are later removed, or poured onto corrugated sheet metal supports that are left in place. In both cases passages through the concrete decks are needed for various plumbing pipes, electrical conduits, ventilation tubes, etc. In the event of fire or flooding, these passages through the concrete must be sealed in order to prevent passage of air, smoke, fire or water. Current fire and smoke seals use an intumescent material that involves taking flat strips of intumescent material and fastening it around a cylindrical container of predetermined diameter using adhesives or other mechanical fasteners. The intumescent material often includes a graphite or fibrous material that can be messy and hazardous to handle and ingest, and often carcinogenic. Fastening the flat strips to the passage tubes is labor intensive, prone to errors and may raise health concerns. Because the intumescent material has a limited expansion, and because many applications require effective internal smoke and water sealing, the containers are generally made to order for specific pipe sizes. Further, because of the variable thickness of concrete slabs specified by builder contractors, manufacturers are forced to either custom build the container hardware or to supply containers in large increments that force customers to buy extra kits or cut the container on-site. In any event, current options do not allow economically effective manufacturing-to-specification solutions. Upon installation, the pipes actually used may differ from those initially planned or may be offset from the center more than the expansion of the intumescent material can accommodate, so the prefabricated, size specific fire seals may not fit, or fit as well as intended or needed, or may not work as well as designed during actual use. There is thus a need for an improved fire seal and container for intumescent material that will accommodate a wider variety of pipe diameters within a single device be more easily assembled and installed, and better suit variations in pipe location and slab thickness than devices currently used.
The passages through the concrete are formed by fastening a passage tube, typically plastic or metal to the support before the concrete is poured. The concrete decks vary greatly in thickness from four to eight inches, but may be as thin as two inches and as thick as 18 inches or more. Current passage tubes are premade to specific diameters and lengths, making it difficult to stock a sufficient supply for use and to accommodate variations in the passage tubes at the job site. There is thus a need for a more flexible length passage tube able to accommodate pipes of varying diameters.
The tubes must be fastened to the plywood support, or have a larger base to span enough corrugations to provide a stable tube support, especially for smaller diameter, longer passage tubes. Providing a large base suitable for corrugated supports is expensive and unnecessary for plywood supports. Moreover, several pipes may sometimes be clustered together when passing through the floor and in such cases the individual passage tubes need to be placed close together at distances driven by CISPI standards. If the passage tube has a large base for use on a corrugated support, it becomes difficult to achieve the desired spacing when the large support is used on either plywood or corrugated supports. There is thus a need for an improved tube support more suitable for the different support applications.
The passage tubes are provided in different lengths to accommodate the variable thickness of the concrete decks. Long passage tubes are sometimes cut shorter, wasting material and often resulting in inaccurate cuts as the worker may measure wrong. Sometimes an extension can be added to a shorter passage tube to increase the overall length, but again workers can measure wrong, resulting in non-compliant passages through the concrete. Also, the extended tubes may be hit, kicked or stood on and in such cases extension tubes may break. There is thus a need for an improved passage tube with a sturdier, easily adjusted length.
In addition to a smoke and fire seal the passages through the concrete must provide a water seal around the pipes or conduits passing through the passage tube. Flat, plastic or rubber sheets are used with holes cut out for the pipe to pass through and these are also installed in the passage tube at the time the passage tubes are made. If the pipes are too large for the holes the sheets tear, if the pipes are too small the seal is poor and if the pipes are offset from the holes in the sheets then inadequate seals may formed. There is thus a need for an improved water seal in passage tubes.
When the concrete deck is poured around the passage tubes the upper end of the tubes are blocked to prevent concrete from filling the passage tube. Mechanical trowels and riding trowels are used to finish the concrete surfaces of the poured decks and the closed ends of the tubes are often covered with a thin layer of concrete in doing so. The concrete covering makes it difficult to locate the passage tubes. Workers sometimes tape nylon strands to items over which concrete is poured so the strands extend out of the concrete surface after finishing and bend for the troweling machines. But taping strands to things is time consuming, may be unintentionally omitted or not planned at all, and the tape may tear lose or otherwise fail to restrain the strands during pouring of the concrete or troweling. There is thus a need for an improved way to locate passage tubes in freshly poured concrete floors.
The passage tubes may need to be configured differently depending on whether they are to contain metal or cast iron pipes or plastic pipes, in part because the water seal with the outside of a cast iron pipe has different requirements than for plastic or copper pipes. For example, exterior pipe diameters differ significantly between pipe types of even the same nominal internal size. Workers can sometimes look inside the passage tube to see the opening size in the water seal but that is time consuming, and invites error from judging opening diameters by visually looking down a dark tube of varying length. There is thus a need for an improved way to allow workers to identify the types of pipes a passage tube is designed to accommodate.